QT and QT dispersion intervals in long-standing and moderately active rheumatoid arthritis: results from a multicentre cross-sectional study

To define the prevalence of prolonged QT interval and QT dispersion (QTd) in rheumatoid arthritis (RA) patients and in a control population. QT interval corrected by Bazett's formula (QTc) was calculated from standard 12-lead ECGs in 963 subjects free of previous cardiovascular events (646 RA patients and 317 controls strictly matched for age, sex and cardiovascular risk factors). RA patients (59.6±9.6 years, 68.1% females) had a long mean disease duration (10.6 years) and moderate disease activity (DAS28=3.68±1.23). QTc was 5 msec longer in RA patients than in controls (412±9 vs. 407±28 msec, p=0.013). However, the prevalence of QTc prolongation in RA patients and controls was not significantly different (5.3% vs. 6.3%, p=0.50). On the contrary, RA patients had a significantly greater QTd (42±26 vs. 35±18 msec, p